Many systems use multiple modules that are daisy-chained or coupled in series, where the ground potential of one module is set by a prior module. For example, many systems use batteries coupled in series to form a battery stack. If each battery is designed to provide +5V and each module includes ten batteries, the first module can have a 0V ground potential, the second module can have a +50V ground potential, the third module can have a +100V ground potential, and so on. Depending on the number of batteries and modules used, a module could have a +500V ground potential or more. Example systems where this may occur include photovoltaic (PV) or solar power farms, battery charging systems, and the like. These high-voltage ground potentials can present a problem if a controller at a +0V ground potential needs to communicate with the modules since each module is at a different reference potential.